Casting-off device

ABSTRACT

An underwater casting-off device automatically releases when the retained payload impacts on the ocean bottom. The device has two vertical arms, pivoted together, which form at least one castingoff hook or eye. Displacement of the arms about the pivot opens or closes the hook or eye. A transverse member, weighted at one end and pivotally mounted to the top of one arm restrains the arms from opening while held at right angles to the arms. The equipment to be cast-off is automatically released when impact with the ocean floor causes the transverse member to incline downward, releasing the arms and opening the hook or eye. The device includes a means for attaching floats to the transverse member. Locking means are provided by a water soluble plug, as is an elastic mechanism to return arms to a locked position following the equipment release.

United States Lepetit et a1.

I: ate .1 l [1 1 CASTING-OFF DEVICE Inventors: Marcel Lepetit; Christian Charles,

both of Brest; Jean Nonnet, Guilers; Francois LeFoll, Brest, all of France [73] Assignees: Le Nickel; Centre National pour IExploitation des Oceans, both of Paris, France Filed: July 17, 1973 App]. No.: 379,939

[30] Foreign Application Priority Data July 19, 1972 France 72.26060 [56] References Cited UNITED STATES PATENTS 11/1890 Prichard 294/83 R 11/1922 Foxhall 294/83 R 2/1931 Hopkins l 294/84 3/1953 Richardson 294/118 X [451 May 219, 1975 2,791,785 5/1957 Metts 9/9 3,186,752 6/1965 Kaplan et al..... 294/104 3,228,080 1/1966 Tranger 294/83 R X Primary Examiner-Evon C. Blunk Assistant ExaminerJohnny D. Cherry Attorney, Agent, or Firm-Fleit & Jacobson [57] ABSTRACT An underwater casting-off device automatically releases when the retained payload impacts on the ocean bottom. The device has two vertical arms, pivoted together, which form at least one casting-off hook or eye. Displacement of the arms about the pivot opens or closes the hook or eye. A transverse member, weighted at one end and pivotally mounted to the top of one arm restrains the arms from opening while held at right angles to the arms. The equipment to be cast-off is automatically released when impact with the ocean floor causes the transverse member to incline downward, releasing the arms and opening the hook or eye. The device includes a means for attaching floats to the transverse member. Locking means are provided by a water soluble plug, as is an elastic mechanism to return arms to a locked position following the equipment release.

5 Claims, 3 Drawing Figures PATENTED ammsrs SHEET 1 [IF 2 CASTING-OFF Device The present invention relates to a casting-off device, particularly for use with underwater exploration apparatus. It is known that such apparatus, which may be sampling devices or photographic apparatus, are ballasted, attached to one or more floats, generally by means of a cable, and released at the surface of the water to be explored. This assembly sinks under the effect of the ballast and, when it touches the sea-bed, carries out operations such as casting-off the ballast and picking up samples or taking photographs, with the aid of equipment which will not be described in this specification. When the ballast has been cast off, the remainder of the assembly rises to the surface of the water with the aid of floats, and can then be recovered.

Whatever the type of exploration envisaged, the assembly should include at least one casting-off device which detaches one or more elements when the assembly touches the sea-bed.

Thus, in the case of an exploration apparatus comprising photographic equipment, the casting-off device has to release ballast to enable the apparatus to rise again to the surface under the action of the floats. If the apparatus concerned comprises a sampling device of the type described in our French patent application No. 72-26061 filed on July 19, 1972, the casting-off device has to release two cables from each other, thus simultaneously activating the sampling device for operation and casting-off the ballast.

To summarize the foregoing, it can be said that a required function of the device in accordance with the present invention is to operate apparatus connected to a float by a cable, under the effect of the impact caused when the equipment strikes the sea-bed.

Hooks which may be operated to release various objects, while being normally locked in their closed position, are already known, for instance from US. Pat. No. 1,793,401. These known hooks usually comprise two pivoted arms which are displaceable between an open position and a closed position in which they are disposed substantially one behind the other, the arms being so shaped as to form, near the pivot point, at least one casting-off hook which is open when said arms are in the open position and closed when these arms are in the closed position, and a locking member slidable over the arms being provided to lock the hook against move ment.

Obviously, such a hook cannot be used for releasing underwater exploration devices since it is unlocked by sliding its locking member over the arms, and this cannot be performed automatically in a reliable manner when the apparatus touches the sea-bed.

An object of the present invention, therefore, is to provide a casting-off device of this kind which can be used for automatically actuating underwater exploration apparatus when the apparatus touches the sea-bed.

Another object of the present invention is to provide a casting-off device of the kind which operates in a reliable manner and prevents premature actuation of the apparatus.

A further object of the invention is to provide a device of the kind that is of simple construction, robust, and inexpensive.

According to the present invention there is provided a casting-off device of the kind comprising two arms which are pivoted together to be displaceable between a closed position in which they are disposed substantially one behind the other and an open position, and which arms are so shaped as to form, near their pivot point, at least one casting-off hook or eye which is open when said arms are in the open position and closed when these arms are in the closed position, characterized in that:

A transverse member which is effectively weighted at its one end is pivotally mounted at a point near its other end on one of said arms, the transverse member being displaceable between a locking position in which it is at approximately right angles to said arms and a release position in which it is inclined from said pivot point; a stop is provided at the said other end of said transverse member; a retaining element to coact with said stop is provided at the end of the other of said arms, said retaining element engaging said. stop when the transverse member is in the locking position and releasing said stop when the transverse member is in the release position; means for connecting at least one float to said transverse member are located on the transverse member between its weighted end and said pivot point; and, for the purpose of locking said pivoted arms in the closed position by means of a water-soluble peg, holes are formed in the arms to be in register when the arms are in the closed position.

' It will be appreciated that the apparatus to be cast off may be secured to the casting-off hooks, for example by means of at least one cable. I

In a first form of construction, which will be used if the apparatus to be cast-off is connected to the device of the invention by two cables applying two symmetrical lateral forces, as is the case with the sampling device described in our abovernentioned patent application No. 72-26061, the arms'are pivoted near their lower ends, remote from the transverse member, and the arms are so shaped as to form two symmetrical hooks or eyes which are either fully closed or open at the side depending upon the position of the pivotal arms. In this case, each of the eyes can be formed by an inwardly curved finger on one of the arms and a transverse closure part on the other arm.

In another form of construction, used when the force applied on the hook or eye by the apparatus to be cast off is directed downwardly substantially along the vertical axis of the device, the pivotal arms are of scissorlike form and, between the pivot point and their lower ends, they are of curved or angled shape so as to form a hook or eye which is closed! or open depending upon whether the arms are in the closed or open position. In this latter case, it is advantageous to provide a return means fitted between the pivotal arms so as to urge them into the open position.

In both forms of the invention the stop formed on the transverse member is advantageously made of a flange of U-shaped cross-section at the end of the member and which, when the transverse member is in the locking position, caps the upper end of that arm on which the transverse member is not pivoted.

Said means for locking the pivotal arms in the closed position preferably comprise a peg which can be inserted into two holes which are formed in the pivoted arms and which move into register when these arms are in the closed position. It is advantageous for this peg to be made of a water-soluble substance such as barley sugar, so that it can be operative when the apparatus is lowered into the water but will have disappeared when the exploration apparatus reaches the sea-bed.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of one form of casting-off device according to the invention;

FIG. 2 is a detail plan view of part of the device shown in FIG. 1; and,

FIG. 3 is a side elevation of a further form of castingoff device according to the invention.

The casting-off device illustrated in FIGS. 1 and 2 is designed for use with an apparatus which applies to the device two lateral forces indicated in FIG. 1 by arrows F. This is the case when the apparatus comprises the sampling device described in the above patent application No. 72-26061.

For the sake of clarity, it will be assumed that the device of the invention is in the operating position, for example descending towards an underwater bed, and expressions such as vertical and upper part are to be read in this light.

The casting-off device illustrated in FIG. 1 includes two arms 1 and 2 pivoted .at their lower ends about a shaft 3 and having the form of two rigid blades which can be disposed one behind the other over the greater parts of their lengths. A transverse member 4 is mounted to rotate on a pivot 5 at the upper end of the arm 2 and carries a counterweight 6 at its free end remote from the pivot 5.

The arm 1 is shorter than the arm 2 and is provided with a projection 7 at its upper end. When the device is closed, the two arms 1 and 2 are disposed substantially one behind the other and, when the transverse member 4 is in the horizontal position, the device is prevented from opening by a flange 8 of U-shaped cross-section which is formed at the pivoted end of the member 4 and which hold the projection 7 as shown in FIG. 2. On the other hand, when the transverse member 4 is lowered, the flange 8 disengages from the projection 7, and the pivoted arms 1 and 2 are free to open as shown in broken lines in FIG. 1. The height of the projection 7 is selected to suit the required delay in effecting release.

At their lower ends the arms 1 and 2 have transverse fingers 9 and 10, respectively, which are curved upwardly, the two symmetrical fingers extending in opposite directions to each other. At a slightly higher point, the arms 1 and 2 have lateral closure parts 11 and 12, respectively, these two symmetrical parts extending in opposite directions to each other and each in a direction opposite to that of the finger of the same arm. In other words, as illustrated in FIG. 1, the finger 9 on the arm 1 extends to the right and the lateral closure part 11 on the same arm extends to the left, whereas the finger on the arm 2 extends to the left and the lateral part 12 of this arm extends to the right. When the device is closed, the finger 9 and the closure part 12 on the other arm form a first closed hook or eye 13 and, in the same way, the finger 10 and the lateral closure part 11 form a second eye 14 disposed symmetrically in relation to the first eye. As shown in broken lines in FIG. 1, these eyes open outwardly when the arm 1 swings clockwise about the pivot 3.

At a point corresponding approximately to a fifth of the length of arm 2 measured from the top, each of the arms 1 and 2 is provided with a lateral extension 15,

15a, each extension containing a hole 16. The holes 16 move into register when the device is closed, so that a peg 16' made of water-soluble material can be inserted to hold the arms 1 and 2 in the closed position. The lateral extension 15a of the arm 2 has a flange of U- shaped cross-section, as shown in FIG. 2, and this flange acts as a stop for the arm 1 when the pivoted arms are closed. The transverse member 4 has a hold 17 between the counterweight 6 and the pivot 5, but much nearer to the latter; through this hole is passed cable 18 which connects the device to the floats mentioned previously.

The device shown in FIGS. 1 and 2 operates in the following manner.

The apparatus to be cast off is connected to the device, in the open position, by means of, for example, two cables passed through the eyes 13 and 14; as mentioned above, the cables apply the lateral forces illustrated in FIG. 1 by the arrows F. It is, of course, possible to equip these cables with means such as shackles, i.e. bowed elements fitted with bolts, and to pass the shackles into the eyes. When this operation has been carried out, the pivotal arms are closed and a peg made of water-soluble substance, for example barley sugar, is inserted into the aligned holes 16. The floats for the exploration assembly are attached to the casting-off device by the cable 18 passed through the hole 17.

The assembly can then be submerged, and it descends towards the sea-bed under the action of ballast, not shown. During the descent of the assembly, the peg dissolves, but the arms 1 and 2 are kept closed by the locking action of the flange 8 of the transverse member 4 on the projection 7 of the arm 1. The transverse member 4 is held in the horizontal position as a result of the opposing effects of, on the one hand, the tension in the cable 18 which is passed through the hole 17 and connects the device to the floats and, on the other hand, the weight of the exploration apparatus acting on the lower part of the device.

When the assembly reaches the sea-bed, the tension in the cable 18 is reduced, and the weight and momentum of the counterweight 6 lower the transverse member 4 which releases the arm 1. Thus, the device opens, under the action of the lateral forces F, the peg having dissolved. The cables or the shackles of the exploration apparatus are then freed from the eyes 13 and 14 and move out under the effect of the lateral forces F, so that the apparatus is cast off. The casting-off device itself rises to the surface as a result of the pull applied by the floats, through cable 18.

In the form of device illustrated in FIG. 3, the same reference numerals as in FIG. 1 are used for parts that are identical to or perform the same function as those bearing those reference numerals in FIG. 1. The form of device shown in FIG. 3 is intended for use where the apparatus to be cast off applies a substantially vertical force F which is, of course, directed downwardly.

The device of FIG. 3 has pivoted arms 1 and 2, but their pivot 3 is spaced above their lower ends. Between the pivot 3 and their lower ends, the scissor-like arms are angled to extend first outwardly and then inwardly so that they form a hook or eye 20 when the device is in the closed position. In the open position of the device, as illustrated in broken lines in FIG. 3, the eye 20 is open at the bottom.

The upper part of the device is similar to that of the device illustrated in FIG. 1. Again, there is provided a transverse member 4 with its counterweight 6 and its flange 8 of U-shaped cross-section, and a projection 7 formed at the upper edge of the arm 1. On the other hand, the lateral extension of the arm 1 in this arrangement comprises a downwardly extending portion to which there is secured a bolt 22, and a similar bolt 21 is mounted on the arm 2 at a point near its lower end and remote from the axis of symmetry of the arm assembly. A resilient return member 23 made of, for example, a synthetic material such as NEOPRENE, is stretched between the bolts 21 and 22. The function of member 23 is to ensure that the device remains open upon removal of the locking action due to the peg fitted in the holes 16 and due to the projection 7 bearing against the flange 8. It should be noted that this return member would serve no useful purpose in the device illustrated in FIG. 1 where the lateral forces F applied by the device to be cast off urge the device to the open position.

The method of operation of the device shown in FIG. 3 does not require to be described in detail, since it is virtually the same as that of the form of device shown in FIG. 1. It suffices to state that, when the apparatus to be cast off touches the sea-bed, the peg having dis-- solved and the cross member 4 being lowered, the pivoted arm 1 is released and the cable or retaining shackle is released downwardly; in the FIG. I arrangement, of course, there are two cables or shackles which are released in the lateral direction.

It is also to be noted that, in the two forms of construction which have been described, the pivot 3 may be of sufficient length to guide the casting-off device in relation to the exploration apparatus, for example by its being passed through slots formed in plates integral with the apparatus.

,What we claim is:

-1. A casting-off device of the kind comprising two arms which are pivoted together to be displaceable between a closed position in which they are disposed substantially one behind the other and an open position,

and which arms are so shaped as to form, near their pivot point, at least one casting-off hook or eye which is open when said arms are in the open position and closed when these arms are in the closed position, characterized in that:

a transverse member which is effectively weighted at its one end is pivotally mounted at a point near its other end on one of said arms, the transverse member being displaceable between a locking position in which it is at approximately right-angles to said arms and a release position in which it is inclined from said pivot point; a stop is provided at said other end of said transverse member; a retaining element to coact with said stop is provided at the end of the other of said arms, said retaining element engaging said stop when the transverse member is in the locking position and releasing said stop when the transverse member is in the release position; means for connecting at least one float to said transverse member are located on the transverse member between its weighted end and said pivot point; the pivot point of said arms is disposed near that end of each of said arms that is remote from said transverse member, the arms being so formed as to constitute, near the pivot point, two symmetrical casting-off hooks which are either completely closed or open at the side, depending upon whether the arms are in the closed or open position; and, for the purpose of locking said pivoted arms in the closed position by means of a water-soluble peg, holes are formed in the arms to be in register when the arms are in the closed position.

2. A casting-off device according to claim 1, in which said peg is made of barley sugar.

3. A casting-off device according to claim 1, in which each of said casting-off hooks is constituted by an inwardly curved finger formed on one of said arms and by a transverse closure part integral with the other arm.

4. A casting-off device of the kind comprising two arms which are pivoted together to be displaceable between a closed position in which they are disposed substantially one behind the other and an open position, and which arms are so shaped as to form, near their pivot point, at least one casting-off hook or eye which is open when said arms are in the open position and closed when these arms are in the closedposition, characterized in that:

a transverse member which is effectively weighted at its one end is pivotally mounted at a point near its other end on one of said arms, the transverse member being displaceable between a locking position in which it is at approximately right-angles to said arms and a release position in which it is inclined from said pivot point; a stop is provided at said other end of said transverse member; a retaining element to coact with said stop is provided at the end of the other of said arms, said retaining element engaging said stop when the transverse member is in the locking position and releasing said stop when the transverse member is in the release position; means for connecting at least one float to said transverse member are located on the transverse member between its weighted end and said pivot point; said arms which are pivoted in the manner of scissors and are so shaped between said pivot point and that end remote from said transverse member so as to form a hook which is either completely closed or open at the side of said end remote from the transverse member, depending upon whether the arms are in the closed or open position; a return means provided between said arms to urge the arms to the open position and, for the purpose of locking said pivoted arms in the closed position by means of a water-soluble peg, holes are formed in the arms to be in register when the arms are in the closed position.

5. A casting-off device according to claim 1, in which said peg is made of barley sugar. 

1. A casting-off device of the kind comprising two arms which are pivoted together to be displaceable between a closed position in which they are disposed substantially one behind the other and an open position, and which arms are so shaped as to form, near their pivot point, at least one casting-off hook or eye which is open when said arms are in the open position and closed when these arms are in the closed position, characterized in that: a transverse member which is effectively weighted at its one end is pivotally mounted at a point near its other end on one of said arms, the transverse member being displaceable between a locking position in which it is at approximately right-angles to said arms and a release position in which it is inclined from said pivot point; a stop is provided at said other end of said transverse member; a retaining element to coact with said stop is provided at the end of the other of said arms, said retaining element engaging said stop when the transverse member is in the locking position and releasing said stop when the transverse member is in the release position; means for connecting at least one float to said transverse member are located on the transverse member between its weighted end and said pivot point; the pivot point of said arms is disposed near that end of each of said arms that is remote from said transverse member, the arms being so formed as to constitute, near the pivot point, two symmetrical casting-off hooks which are either completely closed or open at the side, depending upon whether the arms are in the closed or open position; and, for the purpose of locking said pivoted arms in the closed position by means of a water-soluble peg, holes are formed in the arms to be in register when the arms are in the closed position.
 2. A casting-off device according to claim 1, in which said peg is made of barley sugar.
 3. A casting-off device according to claim 1, in which each of said casting-off hooks is constituted by an inwardly curved finger formed on one of said arms and by a transverse closure part integral with the other arm.
 4. A casting-off device of the kind comprising two arms which are pivoted together to be displaceable between a closed position in which they are disposed substantially one behind the other and an open position, and which arms are so shaped as to form, near their pivot point, at least one casting-off hook or eye which is open when said arms are in the open position and closed when these arms are in the closed position, characterized in that: a transverse member which is effectively weighted at its onE end is pivotally mounted at a point near its other end on one of said arms, the transverse member being displaceable between a locking position in which it is at approximately right-angles to said arms and a release position in which it is inclined from said pivot point; a stop is provided at said other end of said transverse member; a retaining element to coact with said stop is provided at the end of the other of said arms, said retaining element engaging said stop when the transverse member is in the locking position and releasing said stop when the transverse member is in the release position; means for connecting at least one float to said transverse member are located on the transverse member between its weighted end and said pivot point; said arms which are pivoted in the manner of scissors and are so shaped between said pivot point and that end remote from said transverse member so as to form a hook which is either completely closed or open at the side of said end remote from the transverse member, depending upon whether the arms are in the closed or open position; a return means provided between said arms to urge the arms to the open position and, for the purpose of locking said pivoted arms in the closed position by means of a water-soluble peg, holes are formed in the arms to be in register when the arms are in the closed position.
 5. A casting-off device according to claim 1, in which said peg is made of barley sugar. 